Development and Mechanistic Studies of Oxidative Prins-Semipinacol Cyclization Reactions

This work shows that allylic alcohols or silyl ethers promote hydride abstraction leading to direct carbon–carbon bond formation or carbon–oxygen bond formation followed by rearrangement, providing the stereoselective construction of spirocyclic ethers through a Prins-semipinacol pathway. A kinetic isotope effect study showed that hydride abstraction is the rate-determining step, consistent with the presence of a distal nucleophilic group lowering the transition state free energy of the oxidation step.